posted on Apr, 13 2019 @ 03:50 PM
a reply to: anzha
SR-71/A-12 family is essentially a modified delta. Goes pretty high... Goes pretty fast.
Concorde flew at ~50,000' ... Going pretty fast.
B747 typically flies under 42,000'... Doesn't go as fast.
An airplane needs X amount of lift to fly if it weighs X pounds.
X= L = Cl * A * .5 * r * V^2
Cl or coefficient of lift depends on the wing's sectional shape relevant to oncoming air
A is area
r is the air density (altitude, pressure, temperature related)
V^2 is the velocity of airflow squared
If we want to fly higher where air is thinner and r is decreased, then we need to change another variable to keep L the same. We can't change the wing
shape and area (generally speaking), so you need to change the velocity.
The good news is thinner air is less drag... The bad news is your engines/propellers have less air to work with so unless you're using an engine
designed for altitude work or a rocket that doesn't need much (or any) air for combustion, you cannot raise your velocity enough to make L=Weight.
That's your effective ceiling where each plane tops out.
edit on 13-4-2019 by RadioRobert because: (no reason given)